The company is located in Germany.
My strongest points are:
Previous experience in the aerospace industry with the main Worldwide Companies (Boeing and Airbus)
Very Good connections with Aerospace engineers.
My weaker points are:
Poor connections with aerospace clients.
Poor experience in sales and contracting.

Staff augmentation vs. project work in A&D are really two different companies. Another key segmentation is work that requires certification (NATO Clearance, secret clearance, Airbus/Boeing training, etc).

On staff augmentation, a lot of young firms start off bringing in good ex-employees of the majors and and targeting the supply chain. Often the majors Boeing, Dassault, etc like it when subs use talent that already know the primes practices.

If you are targeting project work, you need to define if you are selling skill or price. If your the best team for converting major assemblies into a stream line lean process, you need to clearly define that and sell it into the targets.

In all cases, you are likely to get your first customers in the supply base. The supply base is likely trying to win a bid or execute a current contract. They want to mitigate risk using temporary labor, especially if you are in a EU labor market.

If your model is to sell outside of the Primes, for example selling aerospace talent to boat manufacturing, I would stick more to project work with a few key initial clients. Create an iconic success. I would also look at the UAV market. There is a lot going on there. Often the people creating UAV's are more controls focused, they might like having someone else be there air frame team.

I was heavily involved in the lean manufacturing movement at McDonnell Douglas and Boeing. Mostly on F/A-18, but also C17, 787, UAVs, etc.

As a start up, you need to focus on prospecting. That is the tool that will give you leads. Furthermore, don't ignore social media. I have been in A&D industry for 20+ years and the sales/marketing process has changed. barryneighbors.com

My own background was nuclear / electrical engineering rather than aviation. And my consulting work since has been in a completely different area. Nevertheless, I own some undeveloped properties related to your field. For example:

AeronauticsConsulting.com

Such addresses convey authority even before the brand's reputation is fully grown. The right domain might open doors for you and help grow industry contacts.

The one I mentioned is just an example that comes to mind. If you'd like to explore such options in general, we can talk in more detail by phone.